The present invention relates to a substance having biological activity, such as anticancer activity, antiallergic activity, immunopotentiating activity, and antioxidation activity, obtained from at least one edible mushroom selected from Lentinus edodes, Flammulina velutipes, Hypsizygus marmoreus, Pleurotus ostreatus, Grifola fondosa, Volvariella speciosa ver. speciosa, Pholiota nameko, Lyophllum decastes, Blanc du pays, Tricholoma matsutake, and Bracket fungi such as Ganoderma lucidum and Phellinus yucatensis (Phellinus linteus), a process for producing the substance, and a preparation containing the biologically active substance.
The present inventors have conducted extensive studies on biological activity of mushrooms for many years. It is known in the art that some species of mushrooms exhibit biological activity such as anticancer effects, immunopotentiating effects, antioxidative effects, hypotensive and hypoglycemic effects. However, mushrooms having no or only a small degree of activity are also advertised as being very efficacious and put on the market.
The present inventors have found that the anticancer effects of mushrooms originate from polysaccarides contained therein from the research results based on a mass of research data, and have conducted studies on a glucan which is the polysaccaride contained in mushrooms. However, the present inventors have found that the glucan, which is a pure simple polysaccaride, exhibits activity by injection, but does not exhibit effects by oral administration.
Since the administration by injection can be carried out only in the hospital or the like and oral administration causes a person less pain, provision of active components from mushrooms effective through oral administration has been strongly demanded.
Accordingly, an object of the present invention is to provide a method for efficiently extracting a biologically active substance exhibiting biological activity such as anticancer activity and immunopotentiating activity through oral administration from mushrooms containing a high concentration of such a substance, and a preparation containing the biologically active substance suitably prepared for use.
As a result of extensive studies to achieve the above object, the present inventors have found that fruit bodies and/or mycelia of edible mushrooms contain a large amount of active substances effective through oral administration. The active substances effective through oral administration are contained in an extract of the mushrooms with water, a hydrophilic solvent, or a mixed solvent of these. The present inventors have found that a fraction having a specific molecular weight range obtained by removing low-molecular-weight and high-molecular-weight fractions from the extract using a molecular sieve method exhibits excellent biological activity. This finding has led to the completion of the present invention.
Specifically, the present invention provides a biologically active substance EEM-S obtained by extracting at least one mushroom selected from Lentinus edodes, Flammulina velutipes, Hypsizygus marmoreus, Pleurotus ostreatus, Pholiota nameko, Grifola fondosa, Volvariella speciosa ver. speciosa, Lyophllum decastes, Blanc du pays, Tricholoma matsutake, Ganoderma lucidum, and Phellinus yucatensis (Phellinus linteus), with water, a hydrophilic solvent, or a mixed solvent of these, and collecting a fraction having a molecular weight of 6,000-60,000 from the extract using a molecular sieve method.
The present invention also provides a process for producing the biologically active substance EEM-S.